High density three dimensional semiconductor die package

ABSTRACT

A semiconductor package is disclosed including a plurality semiconductor die mounted on stacked and bonded layers of substrate, for example polyimide tape used in tape automated bonding processes. The tape may have a plurality of repeating patterns of traces and contact pads formed thereon. The traces each include aligned interconnect pads on the respective top and bottom surfaces of the substrate for bonding the traces of one pattern to the traces of another pattern after the patterns have been singulated from the substrate, aligned and stacked. Semiconductor die such as flash memory and a controller die are mounted on the traces of the respective patterns on the substrate. In order for the controller die to uniquely address a specific flash memory die in the stack, a group of traces on each substrate supporting the memory die are used as address pins and punched in a unique layout relative to the layout of the traces other substrates. By providing each flash memory semiconductor die on a substrate with a unique layout of address traces, each memory die may be selectively addressed by the controller die.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to a semiconductor packageformed of multiple semiconductor die stacked on substrate layers in athree dimensional arrangement.

2. Description of the Related Art

The strong growth in demand for portable consumer electronics is drivingthe need for high-capacity storage devices. Non-volatile semiconductormemory devices, such as flash memory storage cards, are becoming widelyused to meet the ever-growing demands on digital information storage andexchange. Their portability, versatility and rugged design, along withtheir high reliability and large capacity, have made such memory devicesideal for use in a wide variety of electronic devices. These devicesinclude for example digital music players, cellular phones, handheldPCs, digital cameras, digital video camcorders, smart phones, carnavigation systems and electronic books.

Flash memory storage cards come in a number of different configurations,but generally include a semiconductor package housed within a standardsized and shaped enclosure. These standard enclosures include SD (SecureDigital) cards, Compact Flash, a Smart Media, a Mini SD Card, an MMC, anxD Card, a Transflash memory card or a Memory Stick. The semiconductorpackage used in such memory devices includes an integrated circuittypically having passive components, one or more memory chips and, insome configurations, a controller chip mounted on and electricallyconnected to a substrate. Substrates on which the integrated circuit maybe formed include printed circuit boards, leadframes and polyimidetapes. Once formed on the substrate, these integrated circuits aretypically encapsulated in a molding compound which protects theintegrated circuit and removes heat from the package.

Where once memory devices included a plurality of discrete semiconductorpackages, each handling different functions, currently a plurality ofintegrated circuit components may be packaged together to provide acomplete electronic system in a single package. For example, multichipmodules (“MCM”) typically include a plurality of chips mounted side byside on a substrate and then packaged. Another example is asystem-in-a-package (“SiP”), where a plurality of chips may be stackedon a substrate and then packaged.

With form factors being fixed for most of the standard memory cardscurrently in use, there are generally only two ways to increase thememory density within a card: use higher density memory chips, and stackmore memory die in a single package. As the memory card space islimited, the method of stacking more memory chips in a package isgetting more difficult and expensive.

Another concern with fabricating stacked memory die in packages is thestresses to which the stacked die are subjected during the encapsulationprocess. Encapsulation equipment may output an injection force of about0.8 tons to drive the molding compound into the mold cavity. For diehaving a footprint of about 4.5 mm by 2.5 mm, this injection force mayresult in a pressure down on the die of about 1.2 kgf/mm². In the past,semiconductor die were better able to withstand the stress generatedduring the molding process. However, die thicknesses have been reducedto a range of about 2 mils to 13 mils. At these thicknesses, the die areoften not able to withstand the stresses generated during theencapsulation process, and fractures in one or more of the die, known asdie cracking, may occur.

A further concern with stacked memory die is that die are tested afterthey are stacked together and mounted on the substrate. If one of thedie turns out to be defective, due to die cracking or any other reason,the entire die stack must be discarded.

SUMMARY OF THE INVENTION

Embodiments of the present invention relate to a semiconductor packageincluding a plurality semiconductor die mounted on stacked and bondedlayers of substrate, for example polyimide tape used in tape automatedbonding processes. The tape may be provided from a reel having aplurality of repeating patterns of traces and contact pads formedthereon. The traces each include aligned interconnect pads on therespective top and bottom surfaces of the substrate for bonding thetraces of one pattern to the traces of another pattern after thepatterns have been singulated, aligned and stacked.

While still part of the reel, a plurality of semiconductor die may bemounted on the patterns of the substrate. In embodiments, thesemiconductor die may comprise a flash memory array. A controller diesuch as an ASIC may be mounted on patterns from a second reel of tape.The pattern of conductive traces on the reels of tape are formed in thesubstrate so that the conductive traces align with each of the die bondpads on the semiconductor die to allow direct bonding of the die to thesubstrate.

Once the flash memory die are mounted on the substrate, the substratemay be singulated into layers and stacked together. However, in orderfor the controller die to uniquely address a specific flash memory diein the stack, a group of traces on each substrate supporting a memorydie are used as address pins and punched in a unique layout relative tothe layout of the traces other substrates. A hole may be punched throughthe substrate across one or more of the address traces to electricallyisolate selected die bond pad. By providing each flash memorysemiconductor die on a substrate with a unique layout of address traces,each memory die may be selectively addressed by the controller die.

After singulation, the substrate layers are aligned and stacked. Whenthe patterns are aligned, one on top of the other, corresponding tracesand interconnect pads from the different substrate layers may be alignedwith each other. The aligned interconnect pads from respective tracesmay then bonded together in to form an integrated semiconductor package.The completed semiconductor package may be mounted within a pair of lidsto form a finished flash memory card, or another device according to thefunction of the semiconductor die forming the package. The lids may bebonded together by known methods including ultrasonic welding.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a method of fabricating a flash memory cardaccording to embodiments of the present invention.

FIG. 2 is a top view of a length of a substrate for supporting asemiconductor die according to embodiments of the invention.

FIG. 3 is a bottom view of a length of a substrate for supporting asemiconductor die according to embodiments of the invention.

FIG. 4 is a side view of a length of a substrate for supporting asemiconductor die according to embodiments of the invention.

FIG. 5 is a top view of a length of a substrate having a semiconductordie mounted thereon according to embodiments of the invention.

FIG. 6 is a cross-sectional view through line 6-6 in FIG. 5.

FIG. 7 is a top view of a length of a substrate with selected electricaltraces punched according to embodiments of the invention.

FIG. 8 is a top view of the integrated circuit substrate layersingulated from the length of a substrate according to embodiments ofthe invention.

FIG. 9 is a side view of the singulated integrated circuit substratelayers stacked according to embodiments of the invention.

FIG. 10 is a side view of the stacked integrated circuit substratelayers bonded together according to embodiments of the invention.

FIG. 11 is a side view of the bonded integrated circuit stack seatedwithin a lid according to embodiments of the invention.

DETAILED DESCRIPTION

Embodiments of the invention will now be described with reference toFIGS. 1 through 11 which relate to a semiconductor package includingstacked and bonded layers of integrated circuit substrates. It isunderstood that the present invention may be embodied in many differentforms and should not be construed as being limited to the embodimentsset forth herein. Rather, these embodiments are provided so that thisdisclosure will be thorough and complete and will fully convey theinvention to those skilled in the art. Indeed, the invention is intendedto cover alternatives, modifications and equivalents of theseembodiments, which are included within the scope and spirit of theinvention as defined by the appended claims. Furthermore, in thefollowing detailed description of the present invention, numerousspecific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be clear tothose of ordinary skill in the art that the present invention may bepracticed without such specific details.

A method for forming a flash memory card according to embodiments of thepresent invention will now be described with reference to the flowchartof FIG. 1. The fabrication process begins in step 50 with a substrate100, a length of which is shown for example in the top, bottom and endviews of FIGS. 2 through 4, respectively. In embodiments, substrate 100may be a tape typically used in tape automated bonding (“TAB”)processes. Such tapes are conventionally available in reel-to-reelconfigurations, and in embodiments may include a thin, flexibledielectric core 102, such as polyimide or other dielectric film, havinglayers 104 and 106 of conductive material formed on the top and bottomof the dielectric core. The conductive layers 104, 106 may either beelectro-deposited on core 102, or rolled sheets of the conductive layers104, 106 may be attached to core 102 using an adhesive. Layers 104, 106may be copper or copper alloys, Alloy 42 (42Fe/58Ni), copper platedsteel, or other metals and materials known for use on TAB tapes. Layers104, 106 may additionally be plated with silver, gold, nickel palladium,copper or other materials for enhancing the bonding properties of thetraces formed on layers 104, 106 as explained hereinafter.

Core 102 may have a thickness of between 50 to 100 microns (μm), andmore particularly 75 to 85 μm. Layers 104, 106 may be ½ ounce copperwith a thickness ranging between 50 to 100 μm, and more particularlybetween 60 and 80 μm. It is understood that the thicknesses of the coreand conductive layers may vary above and below the above-describedranges in alternative embodiments of the invention.

A conductance pattern may be formed in layers 104, 106 on the dielectriccore 102 in known processes such as chemical etching. In chemicaletching, a photoresist film may be applied to conductive layers 104,106. A pattern photomask containing the pattern of conductive traces tobe formed in layers 104, 106 may then be applied over the photoresistfilm. The photoresist film may then be exposed and developed to removethe photoresist from areas on the conductive layers that are to beetched. The exposed areas are next etched away using an etchant such asferric chloride or the like to define the conductive traces and desiredpatterns in layers 104, 106. The photoresist may then be removed. Otherknown chemical etching processes may be used. The pattern formed onlayers 104, 106 may include electric traces 108 and contact pads 110used as explained hereinafter.

Where substrate 100 is a TAB tape, the tape may be provided from a reelhaving a plurality of repeating patterns 112 of traces 108 and contactpads 110 formed thereon. As used herein, pattern 112 may refer to all ofthe traces 108 or a subgroup of traces 108 in the pattern. Pattern 112 ais formed on a top surface of the substrate and pattern 112 b is formedon the bottom surface. Two instances of the pattern 112 are shown inFIGS. 2 through 4, but a reel of substrate 100 may have a large numberof such patterns. Traces 108 on the top surface of the substrate (traces108 a) are electrically connected to corresponding traces 108 on thebottom surface of the substrate (traces 108 b) by a platedthrough-plugged via 126 (FIG. 4) formed through the core 102. Traces 108a, 108 b each include aligned interconnect pads on the respective topand bottom surfaces of substrate 100 for bonding the traces of onepattern 112 to the traces of another pattern 112 after the patterns havebeen singulated, aligned and stacked as explained hereinafter.

The polyimide tape substrate 100 may have a width of 35 mm, 48 mm, or 70mm, but it is understood that the width of polyimide tape substrate 100may be different than those dimensions in alternative embodiments of thepresent invention. Using a TAB tape as substrate 100 provides advantagesof tight pitch of the conductive traces 108 formed thereon. Line pitchesof 45 μm are known to be achievable on TAB tapes. This allows for highdensity circuits. However, as explained hereinafter, it is understoodthat other media may be used for substrate 100 in alternativeembodiments, including leadframes and printed circuit boards.

Referring now to FIG. 5, a plurality of semiconductor die 114 may bemounted on substrate 100, one semiconductor die per pattern 112, alongthe length of substrate 100. In embodiments, semiconductor die 114 maycomprise a flash memory array (e.g., NOR, NAND, or other type of flashmemory). Such semiconductor die typically include a row of die bond pads122 along opposed sides of an upper surface of the die. The pattern ofconductive traces 108 a is formed in the top layer 104 so that theconductive traces align with each of the die bond pads 122 on oppositesides of the semiconductor die 114 to allow the die bond pads 122 to bebonded to the traces when the semiconductor die 114 is flipped over andbonded to the substrate 100 as explained hereinafter. For simplicity,FIGS. 2 and 3 show ten die bond pads 122 and conductive traces 108 (5 oneach side). However, it is understood that each die and pattern formedon the respective upper and lower surfaces of substrate 100 may includemany more than ten traces in alternative embodiments. For example, aflash memory chip may typically include between ten and fifteen die bondpads on each of the two opposed sides of the die. In such embodiments,substrate 100 would be formed with a like number of conductive traces108.

In embodiments, each instance of a pattern 112 in a reel of substrate100 may be identical to each other pattern 112 from that reel. Thepattern may be customized for a particular semiconductor die 114, suchas for example a given flash memory chip. Thus, in embodiments, eachsemiconductor die 114 mounted to respective patterns 112 on substrate100 shown in FIGS. 2 through 4 may be identical to each other. Asexplained hereinafter, semiconductor die 114 are mounted to substrate100, singulated and stacked to form a package. It is understood thatdifferent types of semiconductor die may be included within the stackedpackage.

For example, in embodiments, the stacked package may also include acontroller chip 114 ₄ as shown in FIGS. 9 through 11 for controllingread, write, and operation of the plurality of flash memory chips. Thecontroller chip 114 ₄ may for example be an ASIC. As is known in theart, such controller chips would typically include a different die bondpad configuration on the upper surface of the chip than would a flashmemory chip. For example, an ASIC chip may include between 40 and 80 diebond pads around the edges of the upper surface of the chip.Accordingly, the substrate 100 to which such a controller chip would bemounted would come from a separate substrate reel, having a patterncustomized to that controller chip bond pad configuration. The patternused on substrate 100 for attaching to a controller chip is known in theart.

Thus, in embodiments, a plurality of flash memory chips may be mountedto respective instances of pattern 112 on a first reel of substrate 100shown in FIGS. 2 through 4 in a first process, and a plurality ofcontroller chips may be mounted to instances of patterns formed on asecond reel (not shown) of substrate 100, and the flash memory chips andcontroller chips brought together in a stacked configuration afterbonding to the respective substrates and singulation as explainedhereinafter. It is understood that the type of semiconductor die whichmay be used in accordance with the principles of the present inventionis not limited to flash memory chips or controllers in alternativeembodiments of the present invention. Moreover, while a single reel ofsubstrate may have all identical patterns as described above, it iscontemplated that a single reel of substrate could include differentpatterns to accept different semiconductor die in alternativeembodiments.

The steps for forming flash memory chips on the substrate 100 shown inFIGS. 2 through 4 are explained hereinafter. It is understood that theprocess for forming controller chips on a substrate may be similar tothe steps described hereinafter for forming flash memory chips onsubstrate 100. Referring again to the flow diagram in FIG. 1, in step52, die 114 are affixed to the upper surface of substrate 100. FIG. 5shows four semiconductor die 114 ₀₋₃, with die 114 ₁₋₃ affixed torespective instances of pattern 112 on substrate 100, and die 114 ₀ready to be flipped and attached to substrate 100. It is understood thatmore or less than four semiconductor die may be affixed to substrate 100in alternative embodiments. As is known, substrate 100 may advancethrough a die attach tool capable of affixing semiconductor die 114 tosubstrate 100 one at a time or batch processes a number at a time. Eachpattern 112 on substrate 100 may include a die attach adhesive 116 foraffixing die 114 to substrate 100. Adhesive 116 may be polyimide, epoxy,and/or other known materials for mounting semiconductor die to asubstrate such as a TAB tape.

As discussed above, the die are mounted to the patterns 112 on substrate100 so that the die bond pads 122 on the surface of die 114 lie adjacentto respective traces 108 a. Once a semiconductor die 114 is mounted tothe adhesive on a pattern 112, the die bond pads may be bonded to therespective traces 108 in step 54 and as shown in FIG. 6. Die bond padsmay be bonded to traces 108 in a known bonding process, such as forexample in a single point thermosonic bond process where each bond padposition is individually bonded using heat, time, force, and ultrasonicsapplied to trace 108 and its respective bond pad. Alternatively, a knowngang bonding process which uses thermo-compression to bond all of thetraces to their respective bond pads at the same time may be used. Asindicated above, traces 108 may be plated with gold or other material toenhance the bond between traces 108 and their respective die bond pads.

As explained hereinafter, the semiconductor and trace assemblies will besingulated from substrate 100 and stacked so that traces in one layeralign with the corresponding traces in the next adjacent layer. Oncealigned, corresponding traces in the respective layers are bondedtogether at their interconnect pads. In the finished assembly, in orderfor the controller die to uniquely address a specific memory die 114 ₀,114 ₁, 114 ₂, or 114 ₃, a group of traces 108 on each pattern 112 areused as address pins and punched in a unique layout in step 46 relativeto the other patterns. That is, referring to FIG. 7, each of fourpatterns 112 in substrate 100 receiving semiconductor die 114 ₀₋₃ mayinclude address traces at₀, at₁, at₂, and at₃. It is understood inembodiments including greater or fewer than four semiconductor die 114,there may be a correspondingly greater or fewer number of addresstraces.

As shown in FIG. 7, semiconductor die 114 ₀ may have traces at₁, at₂,and at₃ punched. That is, a hole 124 may be punched through substrate100 across traces at_(1-3,) to electrically isolate the die bond pad 122at traces at₁₋₃, and prevent signal transfer to or from those die bondpads. Similarly, semiconductor 114 ₁ may have traces at₀ and at₂₋₃punched. Semiconductor die 114 ₂ may have traces at₀₋₁ and at₃ punchedand semiconductor die 114 ₃ may have address traces at₀₋₂ punched. It isunderstood that the specific layout of punched address traces shown inFIG. 7 is by way of example only, and other layouts of punched addresstraces would be understood so long as no two semiconductor die 114 ₀₋₃have an identical layout of punched traces. It is also contemplated thatfor a given number of semiconductor die, such as for example the fourshown in FIG. 7, there may be more than four address traces. In such anembodiment, it would be appreciated that the pattern of punched tracesmay vary, so long as each semiconductor die is provided with a uniquepattern of punched traces relative to the other semiconductor die.

Once substrate 100 has been punched as described above, the respectivesemiconductor die may be tested in step 58. Unlike conventional stackedsemiconductor die, if one of the semiconductor die 114 is defective,that semiconductor die 114 may be discarded without having to discardthe remaining semiconductor die 114. Testing may be performed in a knownprocess for testing electrical performance in semiconductor die. Burn-inmay also be performed in step 60 to detect which if any of the die failunder electrical and/or thermal stresses.

Semiconductor die 114 which pass the electrical test and burn-in may besingulated from substrate 100 in step 62 and as shown in FIG. 8. Asindicated, the substrate 100 which is to form the bottom layer of thestack may be singulated with dimensions that include contact pads 110 onthe bottom layer 106 (shown in phantom in FIG. 8). The contact pads 110will be used for communication between the finished package and externalelectronic devices. The remaining singulated layers including die 114₁₋₃ may be cut to a smaller size that does not include the contact pads110. It is understood that any of the semiconductor die 114 ₀₋₃ may bethe lower-most layer in the stack, and be singulated to include contactpads 110. Moreover, it is possible that a layer other than the lowermostlayer would be the layer to include contact pads 110 for externalconnection of the device.

The respective patterns are singulated into substrate layers 118 ₀₋₃carrying semiconductor die 114 ₀₋₃. The substrate layers 118 ₀₋₃ arethen aligned and stacked in step 64 and as shown in the end view of FIG.9. A further substrate layer 118 ₄ including a different semiconductordie 114 ₄, which may be an ASIC or other controller as discussed above,is also stacked with layers 118 ₀₋₃ as shown.

As indicated above, all of the layers from a single roll of substrate100 have an identical trace pattern. When the patterns are aligned, oneon top of the other, corresponding traces and interconnect pads from thedifferent substrate layers 118 may be aligned with each other. Thealigned interconnect pads from respective traces are then bondedtogether in step 66 to form an integrated package 120 as shown in FIG.10.

In particular, the interconnect pads formed on traces 108 a on the topof a first substrate layer align with and are bonded to the interconnectpads on traces 108 b in the bottom of a next adjacent substrate layer.The interconnect pads of the respective substrate layers may be bondedusing known bonding techniques such as ultrasonic welding or solderingusing a reflow oven. Other bonding techniques are contemplated.

Once a column of aligned, corresponding traces in respective substratelayers 118 are bonded together, the aligned, corresponding traces in therespective layers are electrically coupled. Thus, current sent to aparticular trace will be routed to each corresponding trace in eachlayer of the package 120. This is true unless a trace in a givensubstrate layer has been punched as described above. For those traceswhich have punched out holes 124, the punched holes are located betweenthe interconnect pads and the bond site of traces 108 with the die bondpads 122 on the semiconductor die. Thus, a punched trace willcommunicate an electrical signal to the next adjacent layer, but willnot communicate the electrical signal to its bonded die pad.

Through the above-described arrangement of bonded and punched traces,signals may be both universally and selectively communicated betweencontroller die 114 ₄ and the flash memory die 114 ₀₋₃. For example,power and ground currents may be universally communicated to/from adesignated die bond pad of all flash memory die along the pathestablished by corresponding bonded interconnect pads. Likewise, read,write, and other data or instructions may be selectively addressed bycontroller die 114 ₄ to any one of the memory die 114 ₀₋₃ as a result ofthe pattern of punched out areas 124 on address traces at₀₋₃.

For example, if controller die 114 ₄ was to address one of the memorydie, for example, die 114 ₂, with the punch pattern shown in FIG. 7, thecontroller die could send a signal along address trace at₂. As memorydie 114 ₀, 114 ₁, 114 ₃ all have address trace at₂ punched, the signalwould reach only memory die 114 ₂, and none other. As indicated above, acontroller die 114 ₄ may have many more die bond pads and traces thandie 114 ₀₋₃ and substrate layers 118. Thus, controller die 114 ₄ maysend and receive signals along paths independently of those used by thememory die 114 ₀₋₃.

Once integrated, the package 120 may be mounted within lids 128 in step68 and as shown in FIG. 11 to form a finished flash memory card 132. Itis understood that package 120 and lids 128 may form other devices,according to the function of the semiconductor die forming package 120.The lids may be bonded together by known methods including ultrasonicwelding. Bottom lid 128 includes a plurality of ribs as is knowndefining openings through which contact pads 110 may be accessed byexternal electronic devices to provide communication between package 120and those devices. As contact pads 110 may be recessed within lids 128due to the bending of the edges of the different substrate layers 118when bonded together, a conductor 130 may be provided to allowelectrical connection between contact pads 110 and external connectors.In embodiments, it is understood that the bottom layer 118 ₀ includingcontact pads 110 may not be bent upward into the package, and contactpads 110 may reside adjacent to the openings in lid 128. Conductor 130may be omitted in such embodiments. After package 120 is mounted withinlids 128, the resulting device may be tested in step 70 and thenshipped.

As discussed in the Background of the Invention section, theencapsulation process for semiconductor packages may add cost andcomplexity to flash memory card manufacture. The encapsulation processalso subjects semiconductor die to high compressive and thermalstresses, often resulting in die cracking and non-good die. The flashmemory card 132 described above may be fabricated without theencapsulation process. Another frequent cause of die failure isrupturing of the wire bond typically used to connect a die bond pad to aconductive trace on a substrate. By providing a direct connectionbetween the die bond pad and trace according to the present invention,the wire bond process may also be omitted.

The dimensions of package 120 may vary depending on the number ofsemiconductor die and substrate layers included within the package.However, for a package 120 including four flash memory semiconductor dieand one controller die, the package may have an overall height ofbetween 1.4 and 1.6 mm. With this height, the package 120 may be used ina standard flash memory enclosure, including for example an SD card,compact flash, smart media, mini SD card, MMC and xD card, or a memorystick. Other standard flash memory packages are also possible.

As indicated above, in embodiments, substrate 100 may be a polyimidetape. It is further contemplated that substrate 100 could be a leadframeor a printed circuit board. Where substrate 100 is a leadframe, theleadframe edges extending beyond the mounted semiconductor die could bepinched together and bonded to form a package as shown in FIG. 10 asdescribed above. While printed circuit boards are typically notflexible, other methods may be used to connect correspondinginterconnect pads of the respective substrate layers of the packageshown, for example, in FIG. 9 to form a flash memory or other device asdescribed above.

The foregoing detailed description of the invention has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed. Manymodifications and variations are possible in light of the aboveteaching. The described embodiments were chosen in order to best explainthe principles of the invention and its practical application to therebyenable others skilled in the art to best utilize the invention invarious embodiments and with various modifications as are suited to theparticular use contemplated. It is intended that the scope of theinvention be defined by the claims appended hereto.

1. A semiconductor package, comprising: a plurality of stacked substratelayers including at least a first substrate layer and a second substratelayer, the plurality of stacked substrate layers each including apattern of electrical traces, the pattern of electrical traces on eachsubstrate layer including at least a first trace and a second trace, thefirst trace on each layer electrically coupled to each other and thesecond trace on each layer electrically coupled to each other; aplurality of semiconductor die affixed to the plurality of stackedsubstrate layers, one semiconductor die per substrate layer; a firstopening defined through the first trace on the first layer so that acurrent to the first traces on the first and second substrate layersreaches the semiconductor die on the second substrate layer but isprevented from reaching the semiconductor die on the first substratelayer; and a second opening defined through the second trace on thesecond layer so that a current to the second traces on the first andsecond substrate layers reaches the semiconductor die on the firstsubstrate layer but it prevented from reaching the semiconductor die onthe second substrate layer, the first and second openings allowingunique addressability of the semiconductor die on the first and secondsubstrate layers.
 2. A semiconductor package as recited in claim 1,wherein the first and second openings are formed by punching one or moreholes through the given substrate layer, the one or more holes severingthe one or more electrical traces.
 3. A semiconductor package as recitedin claim 1, wherein the plurality of semiconductor die comprise flashmemory semiconductor die.
 4. A semiconductor package as recited in claim1, wherein the plurality of stacked substrate layers are tape used in atape automated bonding process.
 5. A semiconductor package as recited inclaim 1, wherein plurality of stacked substrate layers is four stackedsubstrate layers and the plurality of semiconductor die is foursemiconductor die.
 6. A semiconductor package, comprising: a pluralityof stacked substrate layers including at least first, second, third andfourth substrate layers, each substrate layer of the plurality ofstacked substrate layers including a pattern of electrical traces, thepattern of electrical traces including: a first electrical trace in eachof the first, second, third and fourth substrate layers, the firstelectrical trace in each stacked substrate layer aligning with acorresponding first trace in each other stacked substrate layer, thecorresponding first electrical traces in the stacked substrate layersbeing electrically coupled together, a second electrical trace in eachof the first, second, third and fourth substrate layers, the secondelectrical trace in each stacked substrate layer aligning with acorresponding second trace in each other stacked substrate layer, thecorresponding second electrical traces in the stacked substrate layersbeing electrically coupled together, a third electrical trace in each ofthe first, second, third and fourth substrate layers, the thirdelectrical trace in each stacked substrate layer aligning with acorresponding third trace in each other stacked substrate layer, thecorresponding third electrical traces in the stacked substrate layersbeing electrically coupled together, and a fourth electrical trace ineach of the first, second, third and fourth substrate layers, the fourthelectrical trace in each stacked substrate layer aligning with acorresponding fourth trace in each other stacked substrate layer, thecorresponding fourth electrical traces in the stacked substrate layersbeing electrically coupled together; a plurality of semiconductor die,one die of the plurality of semiconductor die mounted on each substratelayer of the plurality of substrate layers, the pattern of electricaltraces on a given stacked substrate layer bonded to bond pads on thesemiconductor die on the given stacked substrate layer; and a firstgroup of openings defined through the second, third and fourth traces onthe first substrate layer so that a current to the first trace on thefirst substrate layer reaches the semiconductor die on the firstsubstrate layer, while currents to the second, third and fourth traceson the first substrate layer do not reach the semiconductor die on thefirst substrate layer.
 7. A semiconductor package as recited in claim 6,wherein the first group of openings are formed by punching holes throughthe first substrate layer and second, third and fourth traces, the holessevering the second, third and fourth traces.
 8. A semiconductor packageas recited in claim 6, wherein the plurality of stacked substrate layersis four stacked substrate layers and the plurality of semiconductor dieis four flash memory semiconductor die.
 9. A semiconductor package asrecited in claim 8, further comprising a fifth substrate layer includinga controller semiconductor die for controlling operation of the fourflash memory semiconductor die.
 10. A semiconductor package as recitedin claim 6, further comprising a second group of openings definedthrough the first, third and fourth traces on the second substrate layerso that a current to the second trace on the second substrate layerreaches the semiconductor die on the second substrate layer, whilecurrents to the first, third and fourth traces on the second substratelayer do not reach the semiconductor die on the second substrate layer.11. A semiconductor package as recited in claim 10, further comprising athird group of openings defined through the first, second and fourthtraces on the third substrate layer so that a current to the third traceon the third substrate layer reaches the semiconductor die on the thirdsubstrate layer, while currents to the first, second and fourth traceson the third substrate layer do not reach the semiconductor die on thethird substrate layer.
 12. A semiconductor package as recited in claim11, further comprising a fourth group of openings defined through thefirst, second and third traces on the fourth substrate layer so that acurrent to the fourth trace on the fourth substrate layer reaches thesemiconductor die on the fourth substrate layer, while currents to thefirst, second and third traces on the fourth substrate layer do notreach the semiconductor die on the fourth substrate layer.
 13. Asemiconductor package as recited in claim 6, wherein the plurality ofstacked substrate layers are tape used in a tape automated bondingprocesses.
 14. A semiconductor package as recited in claim 13, whereinone of the singulated substrate layers is singulated to include contactpads for communications between the semiconductor package and anexternal device.
 15. A flash memory package, comprising: a plurality offlash memory semiconductor die; a plurality of stacked tape substratelayers, each stacked tape substrate layer including a flash memorysemiconductor die of the plurality of semiconductor die, the pluralityof stacked tape substrate layers including patterns of electricaltraces, an electrical trace of a pattern of electrical traces in a tapesubstrate layer aligning with a corresponding trace in each other tapesubstrate layer, the corresponding electrical traces in each stackedtape substrate layer being electrical coupled; and a plurality of groupsof openings formed through respective substrate layers of the pluralityof tape substrate layers, a group of openings in each tape substratelayer also formed through all but one electrical trace of the pattern ofelectrical traces on each tape substrate layer to electrically isolateall but the one electrical trace on each tape substrate layer from thesemiconductor die on each tape substrate layer, each group of openingson respective tape substrate layers isolating a different group ofelectrical traces as compared to other tape substrate layers.
 16. Aflash memory package as recited in claim 15, the plurality of flashmemory devices comprising four flash memory devices.
 17. A flash memorypackage as recited in claim 15, further comprising a controllersemiconductor die mounted on an additional tape substrate layer, theadditional tape substrate layer stacked on the plurality of stacked tapesubstrate layers.
 18. A flash memory package as recited in claim 17, theplurality of tape substrate layers supporting the flash memory diecoming from a first reel of substrates and the additional tape substratelayer coming from a second reel of substrates.
 19. A semiconductorpackage as recited in claim 15, wherein the openings in the plurality ofgroups of openings are formed by punching through each tape substratelayer.
 20. A flash memory card, comprising: a flash memory package,including: a plurality of stacked substrate layers, the plurality ofstacked substrate layers each including a pattern of electrical traces,a plurality of flash memory semiconductor die affixed to a stackedsubstrate layer of the plurality of stacked substrate layers, aplurality of groups of openings formed through respective substratelayers of the plurality of substrate layers, a group of openings in eachsubstrate layer also formed through all but one electrical trace of thepattern of electrical traces on each substrate layer to electricallyisolate all but the one electrical trace on each substrate layer fromthe semiconductor die on each substrate layer, each group of openings onrespective substrate layers isolating a different group of electricaltraces as compared to other substrate layers, and a controllersemiconductor die affixed to a stacked substrate layer of the pluralityof stacked substrate layers; and a lid in which the flash memory packageis encased.
 21. A flash memory card as recited in claim 20, the flashmemory card comprising a secure digital (SD) card.
 22. A flash memorycard as recited in claim 20, the flash memory card comprising one of aCompact Flash, a Smart Media, a Mini SD Card, an MMC, an xD Card, aTransflash memory card and a Memory Stick.
 23. A semiconductor packageas recited in claim 20, wherein the openings in the plurality of groupsof openings are formed by punching one or more holes through the givensubstrate layer, the one or more holes severing the one or moreelectrical traces.
 24. A semiconductor package as recited in claim 20,wherein the plurality of stacked substrate layers supporting the flashmemory semiconductor die are singulated from a first reel of tape usedin tape automated bonding processes.
 25. A semiconductor package asrecited in claim 24, wherein the stacked substrate layer supporting thecontroller semiconductor die is singulated from a second reel of tapeused in tape automated bonding processes.
 26. A semiconductor package asrecited in claim 20, wherein plurality of stacked substrate layers isfive stacked substrate layers and the plurality of flash memorysemiconductor die is four semiconductor die.